硒对水稻的生态毒理效应及临界指标研究

Eco-toxicological effects of selenium and its critical value on Oryza sativa

通过土壤添加硒盆栽试验,研究了黄棕壤不同浓度Se对水稻生物量、叶绿素含量、抗氧化酶系统的影响.结果表明,低浓度Se(<8mg·kg-1)对水稻根和地上生物量、叶绿素a含量、叶绿素a/b有促进作用,并整体提高了作物抗氧化酶系统,使MDA下降,SOD、CAT、POD、GSH Px活性相应提高.而高浓度Se(>16mg·kg-1)对水稻根和地上生物量、叶绿素a含量、叶绿素a/b有明显的抑制作用,对抗氧化酶系统产生胁迫效应,使GSH Px明显上升,MDA上升,SOD、CAT、POD酶活性明显下降.各项生理指标与土壤Se处理浓度之间相关分析表明,土壤Se浓度与地上部干重相对百分率、根干重百分率、叶绿素a/b、MDA、SOD、CAT、POD之间有显著相关性.比较胁迫效应10 %值的临界指标EC10值表明,作物地上部干重抑制率作为土壤临界值制定的依据更为可靠,EC10为2 1mg·kg-1.

In a pot experiment with brown-yellow soil,this paper studied the effects of different concentration selenium on the growth and activated oxygen- scavenging system of Oryza sativa.The results showed that low concentration Se (<8 mg·kg~ -1) had a promoting effect on the wheat biomass,chlorophyll a,chlorophyll a/b,and activated oxygen- scavenging system,while high concentration Se (>16 mg·kg~ -1) was in adverse.Soil Se concentration had a significant correlation with root biomass,shoot biomass,chlorophyll a/b,MDA,SOD,CAT,POD.It was defined by the pot experiment that 10% inhibition rate of root or shoot biomass could be regarded as critical value,and the critical content of soil Se was estimated to be 21 mg·kg~ -1.